Extending the wing length of certain commercial aircraft is extremely desirable. Long high aspect ratio wings are aerodynamically more efficient than shorter wings. However, existing airports limit the size of aircraft wing span so the aircraft can fit within their taxiways and parking areas. Some airports might not be able to accommodate aircraft having long wings.
A folding wing design may be used to reduce the span of these wings to fit within the limitations of an existing airport's infrastructure. Folding wing designs enable naval aircraft to operate from the limited deck space of aircraft carriers. Folding wings allow a naval aircraft to occupy less space in a confined aircraft carrier hangar because the folded wings normally rise over the aircraft's fuselage.
However, naval aircraft are much smaller than large commercial aircraft, and present folding wing designs for naval aircraft are optimized to different mission parameters than large commercial aircraft. Wing fold joints in naval aircraft use highly loaded hinges and locking pins acting over very small wing bending reaction moment arms.
In commercial aircraft, a folding wing design may be scaled up. High reaction loads may be overcome by increasing the size of the hinges and locking pins. However, these size increases will increase aircraft weight, and increases in aircraft weight are undesirable because operating costs such as fuel costs are increased. Consequently, the increase in weight negates the advantages offered by the long high aspect wings.